kubuntu does not unmount USB hard drive safely

[sanette]

I claim kubuntu does not unmount USB hard drive safely, while ubuntu does.

Here's why:

If you use the standard GUI tools for umounting (either in dolphin, or through the panel)
the file system is apparently unmounted, but the disk goes on spinning.

Then, when I unplug my 500Gb iomega, I can hear an unpleasant "click" indicating that the head does some brutal stop.

In ubuntu they have "unmount" and "sefely remove". If you select "safely remove", then you can hear the Hard Drive gently spin down. And no noise at all when you unplug.

I believe the kubuntu behaviour can damage the drive.
Can we add a hook before the kde-unmounting ?
(using hdparm -Y or something like this) ?

[dibl]

Re: kubuntu does not unmount USB hard drive safely

I just tried to replicate your report, and I suspect you're right about this. I used a SATA-to-USB adapter to connect an old WD740, and the device notifier reported it correctly, so I opened it with Dolphin. I put my ear as close as I could get, and clicked "safely remove", and I did hear some head action happen. After a few seconds, I pulled the USB connector, and I heard some more head action. I think you're right -- the filesystem was unmounted, but the drive was not "idled" or "parked" or whatever the term of art is.

This is KDE 4.5.2, BTW.

The Kubuntu and KDE developers don't lurk here -- if it's a bug, it needs to be reported via launchpad, or to KDE.

I'm going to boot a different OS running KDE, and see if it is different there. I'm not sure whether to point the finger at Kubuntu or KDE.

EDIT: aptosid, Dolphin KDE 4.5.2 -- the behavior is the same. When I put my finger on the side of this drive, I can feel the head movements. The "tick" that happens upon pulling the USB cable feels the same as the tick when it is connected, and the tick that happens when I click the "safely remove" menu item. Actually the tick (more of a "clunk") that happens when it first pops up the notifier seems the strongest of all the movements. I'm not sure whether to be concerned or not -- I can't say with any certainty that the head movement when the USB connector is pulled is destructive in any way.

[sanette]

Re: kubuntu does not unmount USB hard drive safely

yeah, I can't be 100% sure either that it's bad for the drive, but still,
the fact that ubuntu does it differently seems to indicate something, doesn't it ?

(and for me, the "clunk" when I pull the cable out is the loudest)

Anyway for the moment I'm using hdparm -Y by hand,
and I'd like to add this as hook automatically.

There is a way in KDE to add an action when a device is mounted, so there should be one before it is unmouted

I tried to look into hal, but that's beyond me...

[ardvark71]

Re: kubuntu does not unmount USB hard drive safely

Anyway for the moment I'm using hdparm -Y by hand,
and I'd like to add this as hook automatically.

Hi...

Can I type "hdparm -Y" directly into a terminal or does it need additional commands? Does it do anything else besides bring the hard drive to a stop?

Thanks!

Regards...

[Snowhog]

Re: kubuntu does not unmount USB hard drive safely

Open a console and type:

man hdparm

[GreyGeek]

Re: kubuntu does not unmount USB hard drive safely

I have a WD Passport 320 GB USB HD.

After I click "Safely Remove" on all three partitions their directory entries go blank in Dolphin and they show that they are unmounted. But, I cans till hear the HD spinning. When I unplug the HD the sound I get is like the spinning down of a turbine, not the head-setting click that you folks are reporting.

[Snowhog]

Re: kubuntu does not unmount USB hard drive safely

My external USB Seagate FreeAgent Go 500 GB HDD works fine. I plug it in, Device Notifier pops up telling me it's there, and I open it in Dolphin. When I'm done, I use the safely remove option, wait a few seconds, and unplug it. I've been doing this without any issues.

I'm no HDD manufacturer, but I don't believe that an externally connected HDD is 'turned off' when the option to 'safely remove' is chosen. What is done is a flushing [read:writing] of any unwritten changes stored in the cache to the HDD.

[sanette]

Re: kubuntu does not unmount USB hard drive safely

ardvark71:

something like
sudo hdparm -Y /dev/sda


Snowhog:

there is this link too on that subject:

http://elliotli.blogspot.com/2009/01...-in-linux.html

Again, if kubuntu would do as ubuntu does, I'd be reassured...
Is this something we could ask to KDE developers ?

[dibl]

Re: kubuntu does not unmount USB hard drive safely

Upon thinking about this, here are some things to bear in mind:

- "the" system (as opposed to "your" system) does not know what kind of USB device will be plugged and unplugged -- memory sticks and card readers and cameras, oh my! So however a "solution" is approached, it needs to be robust enough not to screw up the other types of "safe removals".

- it sure would be interesting to get into Gnome enough to learn how they implement the safe removal, to achieve a hard drive shutdown

- KDE has the desktop "service menus" feature -- I don't know whether that could be used to configure "Safely Remove" in Dolphin. I just use KDE as it comes in default configuration, so I'm not experienced with service menus. In other words, the user may already have the power (if not the know-how) to set up what happens when you choose "Safely Remove" in Dolphin.

http://developer.kde.org/documentati...vicemenus.html

http://forum.kde.org/viewtopic.php?f=66&t=90093

[Ole Juul]

Re: kubuntu does not unmount USB hard drive safely

I have recently used several other systems for automounting and what happens is they mount a device when they are accessed. Usually they are automatically unmounted a couple of seconds (configurable) later in order to provide safe removal of the device. IOW, all that happens is that the device is mounted and unmounted exactly the same as if you did it by hand. How that could have different results in K and U buntu is indeed a puzzle. It seems to me that what happens in the device when plugged or unplugged would be up to the device and not the OS. Could the original recognition of the device by hal make any difference? I don't so, but look forward to what others have to say. What could make a difference is if a system did not unmount the device right away. Perhaps (if possible) check the timeout value. It should probably be around 2 seconds.

[ardvark71]

Re: kubuntu does not unmount USB hard drive safely

Hi Snowhog and sanette...

Thanks!

Regards...

[sanette]

Re: kubuntu does not unmount USB hard drive safely

I decided to install the gnome disk utility:

sudo apt-get install gnome-disk-utility

The app is run by
palimpsest

It is quite nice. I am a bit scared because it tells me that my disk has damaged sectors...
It has the "stop the disk for safely removal" option, which indeed stops the disk.

Interesting experiment:

* when I "safely remove" from KDE, the disk is reported as unmounted, but still visible in dolphin.

* instead, when I "safely remove" from palimpsest, the disk is stopped and completely disappears from the system (not visible by dolphin, neither by palimpsest). Exactly as if I pull the cable out.

[kubicle]

Re: kubuntu does not unmount USB hard drive safely

AFAIK, modern hard drives don't really need to have their heads parked before cutting the power (they should have a built-in parking mechanism), but "peace-of-mind" is of course important (and people generally don't like to hear clicking noises from their hard drives), so I'm not against shutting down the hard drive as part of the "safe removal" procedure.

* instead, when I "safely remove" from palimpsest, the disk is stopped and completely disappears from the system (not visible by dolphin, neither by palimpsest). Exactly as if I pull the cable out.

When you say "Exactly as if I pull the cable out", then I'm not sure what's the difference from pulling the cable out, does palimpsest do something more than cut the power from the drive?

[dibl]

Re: kubuntu does not unmount USB hard drive safely

AFAIK, modern hard drives don't really need to have their heads parked before cutting the power (they should have a built-in parking mechanism)

That is my understanding as well, and I do remember the days when it was necessary to "park" the drive heads before pushing the power button to turn off the PC.

http://www.techarp.com/showarticle.aspx?artno=84&pgno=3

I found a 1999 Western Digital publicity piece on the topic: www.wdc.com/en/library/eide/79-880134.pdf

The other thing that probably is useful to remember is the difference between hard drives that are using an "external" power source, i.e. the 9V line from the PSU, or in the case of my experiment, from an external transformer, versus the external USB drives like the IOMEGA Prestige that use the power from the USB 2 connector. All USB circuits are not created equal -- I have read reports of sub-standard USB 2 power causing problems -- basically not enough power available to run the external drive like it is designed to work.

Here are the official USB specs, FYI: http://www.intel.com/technology/usb/spec.htm

[dibl]

Re: kubuntu does not unmount USB hard drive safely

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